The family of curves in which the sub-tangent at any point to any curve is double the abscissa is given by

The branch of botany that deals with the study of plants providing food,fibers,and wood is known as:

The angular resolution of a $10\,cm$ diameter telescope at a wavelength of $5000\,\mathring{A}$ is of the order of:

$CH_3MgBr + CO_2$ $\xrightarrow{\text{Dry ether}} Y$ $\xrightarrow{H_3O^{\oplus}} Z$. Identify $Z$ from the following.

Four convergent lenses have focal lengths $100 \, cm, 10 \, cm, 4 \, cm$ and $0.3 \, cm$. For a telescope with maximum possible magnification,we choose the lenses of focal lengths:

If $10\%$ of a radioactive material decays in $5$ days,then the amount of original material left after $20$ days is approximately ...............$\%$